The effective administration of medications for the treatment of disease symptoms and for the alleviation of pain, i.e., pain management, is an important aspect to the overall treatment of patients for both curable diseases and terminal illnesses. Particularly, the effective administration of medications in patients experiencing chronic pain associated with a terminal illness is particularly important, because such pain management requires constant administration of medication over prolonged periods of time. As a result, the management of pain for terminally ill patients, such as terminal cancer and those afflicted with HIV, has come to the forefront as the medical profession seeks to alleviate pain to allow the patient to comfortably pass away.
Oral administration has been widely utilized in the past for dispensing pain medications such as narcotic and non-narcotic analgesics. However, oral administration is oftentimes not possible due to an obstruction blocking the oral and gastrointestinal tract, or due to severe nausea/vomiting by the patient. Such gastrointestinal problems are often experienced by terminally ill patients whose bodies are slowly deteriorating.
Parenteral administration, or, administration outside of the intestine, such as through bolus injections or slow infusions are also widely utilized. Intravenous (IV) drips are particularly popular for long-term administration of a medication in controlled dosages. However, parenteral administration is invasive and usually painful to the patient. Undesirable local reactions can occur at the site of the injection or infusion, and wheal, or skin elevation, occurs due to the injections or infusions which involve a needle and are subcutaneous, or beneath the skin. Furthermore, parenteral administration of medications may not be possible if there is a lack of peripheral vasculature and blood flow cannot move to certain areas of the body. Also, some terminally ill patients may refuse parenteral administration of medications.
Parenteral administration of medications is also not practical for long-term patient care due to the requirement that proper sites must be utilized for effective administration. Terminally ill patients may not have the physical capability of performing an injection procedure, and if physically able, may not have the knowledge to properly choose an injection site and administer the medication. Thus, while parenteral administration may be effective, a properly trained healthcare provider is usually necessary for administration. When long-term patient care must be provided by an untrained person, injection techniques may become impossible to implement, requiring a patient to stay in a hospital or other medical facility indefinitely.
Rectal administration of medication is widely used for administering a number of different medications, including non-narcotic and narcotic analgesics for pain management, antinausea medications, and steroids. However, currently available rectal administration techniques involve the use of suppositories which contain a fixed dosing of medication. The suppositories are placed within the rectum for one-time, slow, and continuous absorption. Therefore, there is generally no control over the administration rate except that provided by the fixed breakdown of the suppository and the absorption rate of the rectal mucous membrane. As such, suppositories do not provide the needed flexibility in the management of pain which often requires quick bolus administrations to combat acute pain and acute worsening of pain. Furthermore, since suppositories are generally single dose elements, extended care may require the continual insertion of single dose suppositories for continuous pain management. Such continuous monitoring is expensive and often requires a skilled caregiver when the patient is either unable or unwilling to insert the suppository.
For pain management, the intraspinal administration of non-narcotic and narcotic analgesics is important in alleviating acute and chronic pain. Approaches have been developed for delivering high concentrations of medications into the spinal cord; however, all such techniques are invasive and have associated risks related to the use of a catheter or pump for the injection or infusion. Furthermore, most of these techniques are generally expensive, as they require administration and monitoring by skilled medical personnel.
Therefore, alterative methods of administration that are less complex, demanding, and expensive, are desirable.
Recently, the use of the reversal of blood flow in the vertebral venous system or Batson's Plexus for rectal or intravenous administration of medications into selected pelvic region veins has shown promise as a method of administering analgesics and anesthetics at high concentration directly into the intraspinal areas. Reversal of flow in the Batson's Plexus refers to the physical phenomenon of reversal of blood flow in the veins of the vertebral structures when intraabdominal pressure is applied. Normally, the vertebral venous plexus in the pelvis, sacrum and lumbar spine assist in carrying the venous blood from the meningorrhachidian veins of the vertebral structures, including the spinal cord, to the sacrum and sacral plexus, the iliac veins and ultimately to the inferior vena cava and to the heart. However, the vertebral venous plexus or Batson's plexus is valveless so blood is free to flow in any direction. The Batson effect occurs upon increased intraabdominal pressure which causes reversal of pelvic and lumbar venous flow such that venous flow occurs from the sacral venous plexus and inferior vena cava into the meningorrhachidian blood vessels. In short, normal blood flow occurs from the spinal column toward the heart, but under Batson's described effect, blood flow can occur in the opposite direction, providing blood flow back to the spinal area. Using Batson's plexus reverse flow by increased intraabdominal pressure, in conjunction with the administration of analgesics using venous needle or indwelling venous catheter delivery of opioids, anesthetics or other medications into pelvic region veins that drain into the sacral plexus and Batson's plexus, the analgesic or other medication might be more efficiently and effectively administered at high concentrations to the spinal cord to alleviate pain without peripheral intravenous infusions.
Therefore, it is an objective of the present invention to administer medications to patients without the various drawbacks associated with traditional oral, rectal, and parenteral methods of administration discussed hereinabove. Furthermore, it is an objective to administer medication intravenously (IV) with greater flexibility and with central nervous system specific delivery than provided with currently available techniques.
Particularly, it is an objective of the present invention to administer non-narcotic and narcotic analgesics to continuous care and terminal patients for the management of acute and chronic pain.
It is a further objective of the present invention to administer medications in a nonpainful, noninvasive and safe way without incurring the large expense associated with procedures involving administration and continual monitoring by large numbers of skilled caretakers, such as physicians and nurses. Safe, effective and inexpensive pain management in economically depressed, third world countries is particularly important, as these countries often have large numbers of terminally ill patients without the requisite medical staff available.
It is a further objective of the present invention to provide greater flexibility in the administration of medications, both continuously and in bolus dosages and to provide for easy initiation and termination of the dispensing process.
It is a further objective of the present invention to administer medications so that the medications are rapidly and efficiently absorbed into the necessary areas of the body to alleviate the medical condition or the pain associated therewith.
It is also an objective of the present invention to more efficiently and effectively administer medications into the intraspinal area and particularly to administer anesthetics and analgesics into that area for pain management purposes.
It is also an objective of the present invention to more efficiently and effectively administer medications into the intraspinal and systemic circulation of multiple different pharmacologic agents for many different medical reasons. Medication that can be delivered by pelvic region veins and directed into the intraspinal area include any therapeutic or diagnostic agent that can be delivered by IV in any other area of the body. These include steroids, nonsteroidal anti-inflammatory agents, anti-infectives, oncolytics, immune therapies, antibleeding agents, anti-epileptic agents, fluid replacement, radiopaque x-ray imaging agents and magnetic resonance imaging agents, such as gadolinium, and radioactive diagnostic and radioactive therapeutic agents and experimental drugs (such as ziconotide, large molecules, nonpolar molecules, hormones, and immune modulating agents and other compounds, that may not or only poorly cross the blood-brain barrier, or that are poorly or nonabsorbed through the oral or rectal route) that may be useful to treat pain conditions, or hypothermia or hyperthermia therapy of the pelvic venous blood flow for therapeutic purposes.